Angina Pectoris and Carbon Monoxide

Excerpt

To the editor: There are several serious questions that should be raised concerning the lead article in the November 1972 issue (pp. 669-676), "Effect of Freeway Travel on Angina Pectoris" by W. S. Aronow and associates, which was enthusiastically endorsed by an editorial in the same issue (pp. 808-810). The criticisms fall into three major categories: [1] validity of carboxyhemoglobin levels measured, [2] design of the study, and [3] conclusions drawn from the results.

1. The levels of carboxyhemoglobin reported by the authors in their subjects after 90 minutes of breathing "freeway air" would appear to be suspect. In fact,